Marquez leads the world championship by 16 points, having won three of his first nine races in the premier-class and been off the podium in just one event.

Marquez also turned the tables on Rossi by overtaking the seven time MotoGP champion at the Corkscrew, just as Rossi had done during his epic battle with Casey Stoner in 2008, en route to victory in Sunday's US MotoGP.

"It is Lorenzo that has to give his crown to Marquez, because last time I won the title was in 2009," replied Rossi. "So unfortunately for some seasons I don't have the crown! Apart from the joke, Marc has done some incredible things. I expected it a bit, but sincerely less than this. Because I thought that maybe he has to do some more mistakes during his first season.

"I was very fast on the 500 in 2000, but I did a lot of mistakes and crashed in the first two races, and maybe for that reason I lost the championship. So it is like Marc is me, but upgraded - the new model!"

Despite his recent drought of title success, Rossi is behind only Giacomo Agostini on the all-time premier-class championship list, while his 80 race victories is more than any other rider in history.

But Rossi believes 20-year-old Marquez can be even better.

"He has all the potential to become the greatest of all time, or better than me, or win more than me," declared Rossi. "Because he is a great talent, with great skills, and is also very young. But now is very early to say because it is a long way. But he has 100 percent of possibility to do that."

Asked to respond to those comments, Marquez said: "It is hard to hear what Valentino says because I will get a red face! Valentino is one of my heroes, one of the most important guys ever in MotoGP - in motorcycles. When you hear those words it is quite impressive, but we know on track it is completely different. You have to try to do your 100 percent. But always it is impressive to hear something like that."

Having achieved so much success as well as legendary status within the sport, Rossi was asked how it felt to be beaten by Marquez.

"I'm good with Marc, I am pleased with Marc also because it is not like I am the world champion of last year and now he beats me and takes the number one," said 34-year-old Rossi, who has returned to Yamaha after two winless seasons at Ducati.

"Instead I am coming from a bad, bad season unfortunately, with bad results and I'm so happy to come back.

"I am at a certain age. I have won a lot of races and championships, but for me it is great to fight with him and the other guys. Race by race I have more feeling that I can stay in front. I can enjoy some good results in the races and the championship and for that I'm happy."

Rossi, who took his first victory since 2010 last month at Assen, is fourth in the championship behind Marquez, Dani Pedrosa and Jorge Lorenzo.

Only one rider in 500cc/MotoGP history has ever won the title at his first attempt - 'King' Kenny Roberts in 1978.